Mohn van vleck



Patented July 3,1894.

.l.| v W I J. VAN VL K'. ELEGTRIGA SWITCH.

I l I I i m i i g I um I i i X E I g I sf b a B) MW. W

- 7 26,4 ATTORNEY.

UNITED STATES PATENT OFFICE.

JOHN VAN VLEOK, OF NEW YORK, N. Y.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 522,332, dated July 3,1894;

Application filed May28,1894. Serial No. 512,595. (NomodelJ To all whomit may concern..- i I Be it known that, I, JOHN VAN VLECK, of

the city, county, andState of New York, have invented a new and usefulImprovement in- -Sw1tches for Electric-Lighting Circuits, of

which the following is a specification.

My invention is an improvement in switches designed for use inconnection with the threewire system ofdistribution, so arranged thatcircuit through the "neutral cond uctor is broken after and made beforeit is established through the positive orjnegative conductors.

hereinafter be more particularly pointed out.

In the accompanyingdrawings Figure 1 is a plan view of my switch. Fig. 2is a side elevation with the coverin section. Figs. 3

I and 4 show two forms of contact fingers. Fig.

5 illustrates diagrammatically the ordinary arrangement of lamps on athree-wire system. Similar letters of reference indicate" like parts.

The form of switch to which my invention is applied is one which is wellknown and in common use. Hence only a brief description of its parts isnecessary.

porcelain or other insulating material.

At the center of the "base A is secured a metal rod, B, which issurrounded by a sleeve, 0, of porcelain made in the shape here shownthat is, it is six-sided; Three sides, a, b, c, are covered with platesof conducting material. The remaining sides are uncovered. The post B isturned by the handle E against the action of the coiled spring F. Onthis post is a pin, G, which enters a re'ce'ssin the upper portion ofthe sleeve-O.

Supported upon the base A are three pairs of metallic supports, H H, I Iand J J, each provided with'an opening, as at K, for the reception ofthe circuit wires, and withscrews, as L, for clamping said wires in saidopenings.

In Fig. 1 the neutralwire dis shown clamped in the support 11 and H. Thewire eis clamped in the supportsJ and J and the wire f in the supportsIand I. From each support extends a contact finger'bearing upon theperiphery i of the sleeve 0. Thus, from the support J there extends ametal contact finger, M, and from the support'J', a metal contactfinger, M. The finger M is therefore above the finger M, and isseparated therefrom,

Fromthe support I extends a finger, N, which is above the finger Nextending from the support-I, and from the support H extends a finger,0, above the finger O extending from the support II. It follows,therefore, that when all of the several fingers rest upon the metalplates 0. b c of the sleeve 0, circuit is made through the switch, andthe current passes from J to J by way of the fingers M M and plate a,from I to Iby way of the fingers N N and plate 0 and from H to H by wayof the fingers O O and plate I). This is the arrangement of the switchwhen the current is turned on. 7

In order to turn the current ofi, the handle E is turned to the right ofthedrawings, Fig. 1, so rotating the post B and movingthe pin G in itsrecess to bear against the sleeve 0, seas to carry said sleeve with itin its rotation. Then, as the sleeve 0 is rotated, the metal plates 01.b 0 move from beneath the tingerswhich rest upon them, and the fingersfall upon the intermediate portions of the sleeve 0, which, as alreadystated, present a I surface of insulating material. Therefore cir- A isthe base, circular in form and made of i M, N N'and O O.

jcuit is broken between each pair of fingers M The difference betweenthe construction above detailed and that already known resides in thefact that in the old form of switch the sleeve 0 has but four sides withbut two plates of metal thereuntoapplied, and there are but 'two pairsof supports and contact fingers instead of three pairs of supports andcontact fingers, as inmy aforesaid construction. It will therefore beapparent that my switch as above described is especially designed fora'three-wire system of distribution.

Now, what I propose to accomplish by my invention is to preventa'current of any kind I from passing by wire e to wire f, and vice Fig.5, I show seven lamps in parallel between the wires d and e and d and f.But suppose that the conditions of the circuit were such that, whileseven lamps existed between (Z and e, but one lamp, 9, existed betweencand f. Then, instead of the current which feeds the seven lamps betweenat and 6 coming back by way of the neutral wire (1, all of it, if theswitch at 72- in said wire were open, would pass through the lamp g,probably destroying the filament or doing other injury. It is clear thatthis could not happen if the circuits in e and f were broken beforeinterruption was made in the wire (1. Conversely it is clear that thesame consequences would happen if the circuit was closed through c and fbefore it was closed through d. What I do, therefore, is to arrange theswitch, the construction of which I have before detailed, in such a waythat circuit is made through the neutral wire cl before it is madethrough the wires 6, f and broken in (Z after it is broken in the wires(2, f. This is done in the following manner: The fingers M M and N N areall alike-that is, all of the same length and general construction.Because they are of the same length and operate at the same time,circuit is made and broken in the wires cand f simultaneously. Thefingers O and 0, however, are diiferently made, and the preferableconstruction for each of them is shown in Fig. 4. Each finger is slitlengthwise, as shown at P, and thus is composed of two parts, one ofwhich, Q, is longer than any one of the fin gers M M, N N, and the otherpart, B, is shorter than any one of the fingers M M N N. I haveindicated this in Fig. 4G by drawing on the side of said figure aline,11 7', which represents the length of any one of the fingers M M or N Nin comparison with the lengths of the parts R Q of the finger 0'.

Now considering the parts as they appear in Fig. 1, it will be obviousthat as the sleeve 0 is turned to the right by the handle E, the fingersM M, N N and the parts R of the fingers O 0' will all leave the contactplates before the parts Q of the fingers O 0; this simply because theparts Q are longer than the other fingers. Therefore, although circuitis broken through the wires f and 6, it remains closed through theneutral wire at until after the part Q of the fingers O 0' pass from thecontact plate I); therefore, in breaking the circuit through the wholesystem, it is obvious that I interrupt the circuit in the wires 2 and fbefore I do so in the wire d. Now considering the fingers as all restingon the uninsulated intermediate sides of the sleeve 0, and that thehandle E be turned still to the right for the purpose now of making thecircuit through the system. Plainly the short contact R of the fingers O0 will pass from the uninsulated portion of the sleeve 0 and meet theplate a before the longer portion, Q, of the fingers O O and before thelonger fingers M M, N N. Therefore circuit will be established throughthe neutral wire cl before it is establishedthrough the Wires 6 and f.

It will be seen that these results are accomplished without changing theordinary and well-known operation of the type of switch hereillustrated, and therefore involve no complication of the devicewhatever, while greatly increasing its value. In Fig. 1 I have shown thefingers as made of laminated plates of metal, and it will be understood,therefore, that each plate of the three here shown as composing onefinger O or O is formed in the manner shown in Fig. 4.

As a modification in the construction of the fingers O and O I may makethem as represented in Fig. 3, each finger being then composed of threeplates of metal, lm, of which m is similar in length to the part R ofthe form of finger shown in Fig. 4 and 7c and Z to the part Q, of theaforesaid form of finger. The curved face of the end of the finger meetsthe curved side of the sleeve 0, as shown in Fig. 1. Obviously the sameresults already detailed will be produced by a finger of this shape, thepart m first meeting the plate on the sleeve 0 in making contact, andthe parts kl leaving that plate last when contact is broken. Theapparatus is provided with the ordinary form of cover, as shown at S,Fig. 2.

I claim- 1. In combination with a three-wire distributing system, threepairs of contact fingers respectively connected to the terminals of eachconductor, a rotary support, and three circuit-closin g plates on theperiphery thereof with each of said plates each pair of fingers makescontact; the fingers connected with the neutral conductor of the systembeing of such length relatively to the fingers connected with the othertwo conductors as that when said contact plates are moved by therotation of said support into contact with said fingers, circuit shallbe closed through said neutral conductor before it is closed through theremaining conductors, substantially as described.

2. In combination with a three-wire distributing system,three pairs ofcontact fingers respectively connected to the terminals of eachconductor, a rotary support, and three circuit-closin g plates on theperiphery thereof with each of said plates each pair of fingers makescontact; the fingers connected with the neutral conductor of the systembeing of such length relatively to the fingers connected with the othertwo conductors as that when said contact plates are moved by therotation of said support out of contact with said fingers circuit shallbe broken through said neutral conductor after it is broken through theremaining conductors, substantially as described.

3. The combination in aswitch for electriclighting circuits of a base A,a rotary support, 0, thereon, having contact plates, at b c, 011 itsperiphery, and three pairs of independently-supported fingers, M M, N N,O

IIO

0, each pair of said fingers being arranged to bear upon one of saidcontact plates; the fingers O 0 being of diiferent length from thefingers M M and N N.

4. The combination in a switch for electriclighting circuits of a baseA, a rotary support, 0, having contact plates, or b c, on its periphery,and three pairs of independentlysupported fingers, M M, N N, O 0, eachpair of said fingers being arranged to bear upon one of said contactplates; the fingers O 0 having a portion greater in length than thefingers M M, N N. v

' 5. The combination in a switch for electriclighting circuits of a baseA, a rotary support, 0, having contact p1ates,a b c, on its periphery,and three pairs of independentlysupported fingers, M M, N N, O 0, eachpair of said fingers being arranged to bear upon one of said contactplates; the fingers O O 20 having a portion less in length than thefingers M M, N N, substantially as described.

JOHN VAN VLECK.

Witnesses:

M. Boson, H. R. MOLLER.

